"We remain at a heightened state of vigilance, but the Department of Homeland Security does not intend to issue an NTAS alert at this time," said Secretary of Homeland Security Janet Napolitano in a statement. "However, our security posture, which always includes a number of measures both seen and unseen, will continue to respond appropriately to protect the American people from an evolving threat picture both in the coming days and beyond."

When reached for comment, the TSA issued this statement to AOL Travel:

"TSA continually evaluates the latest threats and screening measures which are implemented based on the latest intelligence. As always, passengers may notice a variety of security measures at U.S. airports to include the use of explosives detection technology, physical bag checks, random gate screening, canine teams and behavior detection officers. We ask the traveling public to remain vigilant and report any suspicious activity to the authorities."

For those who are still wary of the prospect of backed-up screening lines, here are a few tips from the TSA to keep in mind.

Pack in layers – Alternate between clothing and electronics in carry-on bags. This will allow officers to more easily scan bags.

Check all coats and jackets when possible.

Do not wrap gifts. Otherwise security might be unwrapped for inspection.